Self-locking cable tie strap with a symmetrical structure

ABSTRACT

The cable tie strap, having elongate strap body and a locking head provides for receipt of the cable tie strap in the head in either direction. The cable tie strap includes a hollow locking head and an elongate strap having toothing on each side of the strap. A locking bar is positioned within the hollow head. The strap body may be inserted into the hollow head in either direction. The locking bar is lockingly engagable with the toothing on either side of the strap upon insertion of the strap into the head in either direction.

This is a continuation of application Ser. No. 08/689,466 filed of Aug.9, 1996 now U.S. Pat. No. 5,884,367.

FIELD OF THE INVENTION

The present invention relates to a self-locking cable tie strap withsymmetrical structure.

BACKGROUND OF THE INVENTION

In the state of the art are well-known self-locking cable tie straps forbinding together in a bundle wires or cables for the realization ofharnesses of any kind.

The cable tie straps according to the known art comprise a head partprovided with a retaining tooth or pawl, sometimes realized with ametallic insert, arranged to cooperate with a flexible member integralwith the head and provided with a toothing on one side arranged forengaging in an irreversible way the retaining tooth or pawl at themoment of the fastening of the bundle of cables and wires. These tiestraps according to the prior art have the tooth or pawl in the headthat operate in a unidirectional way and are arranged to cooperate withthe toothing on the flexible member or tail that is provided with thetoothing on one side only.

This known construction of the self-locking tie straps with anirreversible locking entails that owing to the asymmetrical structure ofthe same, at the moment of their application for the binding of cablesor wires it is necessary to pay attention to the direction of insertionof the flexible member or tail to ensure correct engagement and lockingwith the head.

There are also known members for the temporary locking of electricalwires with a releasable locking with a symmetrical structure used forthe temporary locking of electrical cords of electrical or electronicapparatus during the packaging, having a symmetrical structure that ishowever not suitable for assemblies of the industrial type and that donot show the capabilities of locking and safety of locking of the cabletie straps for industrial use mentioned above.

It is also to be remarked that in the cable tie straps for industrialuse to which the present invention is mainly referred, the knownasymmetrical structure does not shown inconveniences when these strapsare applied by hand; a minimum amount of attention on the part of theoperator is sufficient.

However, in the case of binding machines of the industrial type, theasymmetry of the known cable tie straps entails several seriousinconveniences. The cable tie straps according to the prior art owing tothe asymmetry cause a partially free binding at the base of connectionof the flexible part or tail with the head part. This free part at thebase of the head assumes a more or less acute angle in relation to thepull exerted at the binding and related to the diameter of the cables,straining the material of the strap at the connection part with the headpossible development of nicks or breakage at the connection base.

The straps according to the prior art are provided as tapes to allow thefeeding of the tapes to an automatic binding tool.

The asymmetrical shape of the straps according to the prior art fed froman auxiliary distributor is the main origin of jamming of the mechanismof the auxiliary distributor as well as of the binding tool and thefeeding conduit, since the feeding method is based on a transfer of thestrap along a closed path by fluid propulsion (compressed air). Theorientation of the strap is consequently extremely important to ensurethe receiving of the strap within the binding tool into a correctposition.

In order to ensure the correct orientation, systems according to theprior art use a flexible tube having a square or rectangular crosssection that reproduces the outline of the head of the strap andconsequently the strap inserted into an auxiliary device of thedistributor is “shot” along the piping by means of a jet of air,maintaining its orientation.

This method that seems correct became critical and causes inconveniencewhen there is impressed a torsion to the square section piping or whenthe piping itself is bent with a radius shorter than a given limit.

SUMMARY OF THE INVENTION

It is therefore an aim of the present invention to provide a strap inplastic material having a symmetrical shape for the binding of cablethat allows the introduction of the flexible portion (tongue) throughthe head from both sides rendering easier in this way the orientation ofthe strip fed by a jet of air along a tubing.

The symmetry of the strap allows therefore its travel in a piping havinga round cross section eliminating any problem of jamming along a pathdetermining the orientation of the strip with a spontaneous rotation(+90°, −90°) at the entry of the binding tool.

It is another aim of the present invention to provide a symmetricalstrap shaped as a hammer where the connection point of the flexibleportion or tail, provided with toothing on both sides, to the headportion with openings on both sides, is radiuses with a symmetricalradius eliminating the narrow angle open zone and possible cracks orbreakage for tensile stress.

It is another aim of the present invention to provide a symmetricalstrap where the binding locking is determined by a part internal to thehead located on the same axis with the flexible part or tail and by anopposite retaining tooth where the internal portion assumes a correctlocking angle owing to the insertion of the tongue through the head in asense or the other and where when the tension has been impressed byelastic deformation of the tongue the opposite tooth engages further theopposite tooth.

Other aims, features and advantages of the cable tie strap according tothe present invention will become clear from the following disclosurethat shows exemplary and non-limiting embodiments of the invention andfrom the figure of the attached drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view of the self-locking cable tie strap having asymmetrical structure according to the present invention;

FIG. 2 shows a lateral view, partially sectioned of the cable tie strapof FIG. 1;

FIG. 2A shows an enlarged detail of the strap shown in FIG. 2;

FIG. 3 shows an enlarged sectional view of the head part of the strapshown in FIG. 2;

FIG. 4 shows a partial view of what is shown in FIG. 3, in theoperational condition;

FIG. 5 shows a sectional view of the locking arrangement of the cabletie strap in an operative condition of binding of a bundle of cables;

FIGS. 6A, 6B, 6C and 6D show a second embodiment of the locking head ofthe cable tie strap according to the invention;

FIG. 7 shows a plan view of another embodiment of the self-locking cabletie strap having a symmetrical structure according to the presentinvention;

FIG. 8 shows a lateral view, partially sectioned of the cable tie strapof FIG. 7;

FIG. 8A shows an enlarged detail of the step shown in FIG. 8;

FIG. 9 shows an enlarged sectional view of the head part of the strapshown in FIG. 8A;

FIG. 10 shows a partial view of what is shown in FIG. 9, in theoperational condition;

FIG. 11 shows a sectional view of the locking arrangement of the cabletie strap in an operative condition of binding of a bundle of cables;

FIGS. 12A, 12B, 12C and 12D show a further embodiment of the lockinghead of the cable tie strap according to the invention;

FIG. 13 shows a further embodiment of the self-locking cable tie straphaving a symmetrical structure according to the present invention; inplan view;

FIG. 14 shows a sectional view of the cable tie strap of FIG. 13, takenalong plane 14—14;

FIG. 14A is a partial view that shows the relationship of the parts ofthe tie strap of FIGS. 13 and 14 in their operative condition;

FIG. 15 shows yet another embodiment of the self-locking tie straphaving a symmetrical structure according to the present invention inplan view;

FIG. 16 shows a sectional view of the cable tie strap of FIG. 15, takenalong plane 16—16;

FIG. 17 shows yet another embodiment of the self-locking tie straphaving a doubly symmetrical structure according to the presentinvention, in plan view;

FIG. 18 shows a sectional view of the tie strap of FIG. 17, taken alongplane 17—17;

FIGS. 19 and 20 show a sectional view of a modified tail part for theabove tie straps having an irreversible locking toothing and areversible locking toothing in its terminal part.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the drawings and in particular to FIGS. 1, 2, 2A, thecable tie straps shown as a whole in 1 comprises a symmetrical head part2, shaped as a hammer and a tail part 3 ending in a tail end 4. As itwill be better shown in the following, both the head 2, and the tail 3have a mirror-like symmetrical structure, thanks to which the very endof the tail 4 of the strap 1 may be inserted within the locking cavity 5of the head 2 either on the right side or on the left side, as it isshown by the arrows F1, F2 in FIG. 2. The locking action of the tongue 3within the head 2 is performed by effect of the positive locking by asymmetrical tooth or pawl 6 that cooperates with a double sawtoothtoothing 7A, 7B realized on both the larger sides of the tail 3. As itis usual, the tail end 4 of the strap 1 is without toothing and taperedto facilitate its insertion into the head 2 of the strap 1 in theinitial steps of the locking operations of a bundle of cables orconductors.

In a preferred embodiment, the connection part 8, 9 is radiuses with aradius R for a better distribution of the bending stresses at the momentof locking of the strap on a bundle of cables and for preventing itsbreakage near the head owing to large stresses that may occur, asmentioned above, at the moment of fastening, or during the useful lifeof the strap in the operative conditions.

With reference to FIGS. 3 and 4 there will be shown with more detailsthe strap according to the invention. Reference numbers equal to thoseof FIGS. 1 and 2 shown corresponding parts.

The symmetrical head 2 comprises a channel 10 with symmetrical entryopenings 5, for the passage of the tail 3. At the interior of thechannel 10 there is provided a ridge for the positioning of the toothing7A, 7B of the tongue 3, and a tab or movable retaining tooth or pawl 6on a virtual hinge comprising a root 11 radiuses to the body of the head2, a thinned part 12 with two shoulders 13 and 14, and a locking toothproper 15.

During the locking operation, the whole of the retaining tooth 6 mayrotate either in a clockwise or counterclockwise direction with respectto the rest position shown in FIG. 3 according to the direction ofintroduction of the tongue 3 within the cavity provided in the head 2.

The parts 16, 17 of connection of the head 2 with the tail 3 areradiuses for decreasing the stresses as described above.

In FIG. 4, there is shown the structure of FIG. 3 in one of the twopossible locking conditions. For simplicity of disclosure, there isshown only one locking condition; the other locking condition ismirror-like symmetrical, owing to the symmetry of the locking structureaccording to the invention, i.e., it is a simple mirror image that willnot be disclosed in detail.

In this FIG. 4, the cable tie strap is shown in a locking condition inwhich the retaining tooth 6 is shown in the direction of theintroduction of the tail 3 in direction shown y the arrow F3. Anintroduction of the retaining of the retaining tooth 6 that prevents theextraction of the tail 3.

The radiused parts 16, 17 on centers C1, C2 allow, as stated above, thestructure to be rendered more rugged, and also allow a better matingwith the ables of the bundle, one of which is shown in 20. The assemblysituation is shown in FIG. 5 and a further explanation is deemedunnecessary.

In FIGS. 6A to 6D there is shown a second embodiment of the presentinvention, relating to the head 2. Since the modification sown in FIGS.6A-6D relates only to the locking tooth or pawl 6, there will bedisclosed in detail only the structure of the latter, leaving out theremainder of the head 2 which is identical to what has been disclosedhereinbefore.

For a better understanding of the modifications according to FIGS.6A-6D, it is advisable to mention a problem that appears with theconventional cable tie straps and also in those described above.

When the cable tie strap has been locked, the strength necessary for thelocking is concentrated, in practice, in the virtual hinge part 6 (FIG.3). This part 6 cannot be too strong, otherwise the introduction andlocking operation for the strap would be difficult. At the same time itcannot be too yielding, otherwise the quantity of material that hasstrength in the fastening step would be insufficient. The structure anddimensioning of part 6 constitutes therefore a critical element in thedesign and production of this kind of cable tie straps.

The structure shown in FIGS. 6A-6D enables this problem to be overcome.

As it is shown in these Figures, the locking tooth 6′ comprises a rootpart 20 connected with an elastic hinge 21 to a locking body propershaped as a symmetrical polygonal star. This locking body comprisesshadings 22, 22′; 23, 23; 24, 24′. As it is shown in FIG. 6B, during theinsertion operation of the tongue within the head 2, the body 6′ rotatesto the left allowing the passage of the tongue 3 and of the tooth 7A. Inthis connection, owing to the flexibility of the elastic or virtualhinge 21, the shapings 23′, 24′ will be carried outside the outline ofthe tooth 7A, allowing the introduction of the tongue 3 in the directionshown by the arrow F4.

In the condition of simple engagement, the tail 6 will have two teeth7A′, 7A″, in engagement with the shapings 24′ and 23′ (see FIGS. 6A and6C). In this way the positioning is much more stable with respect to theconventional construction.

In condition of finished fastening and/or particular stresses when thecable tie strap is in the operational condition, stressed by the forceindicated by the arrow F5. the locking tooth 6′ will be in engagementwith the shapings 24′, 23′ with the tooth 7A′. 7A″, but owing to theyielding of the elastic hinge 21 the shaping 22 will rest against theleft part of the root 20. In this way the strength to the tear of thetail 6′ will be assured not by the hinge 21 as in the conventionalconstruction, but by the interlocking of the shapings 24, 23′, to teeth7A′, 7A″, shaping 22 and root 20. Consequently the strength to the tearwill be guaranteed by the strength of the tongue 6 and not by the hinge21 with an increase of reliability of the binding extremely higher thanthat of the conventional cable tie straps.

It will be clear that the construction and the operational principle ofthe construction according to FIGS. 6A-6D may also be applied toasymmetrical cable tie straps of the conventional kind.

With reference to the drawings and in particular to FIGS. 7, 8, 8A, thecable ties strap shown as a whole in 101 comprises a symmetrical headpart 102, shaped as a hammer and a tail part 103 ending in a tail end104. As it will be better shown in the following, both the head 102, andthe tail 103 have a mirror-like symmetrical structure, thanks to whichthe tail end 104 of the strap 101 may be inserted within the lockingcavity 105 of the head 102 either on the right side or on the left side,as it is shown by the arrows F1, F2 in FIG. 8. The locking action of thetongue 103 within the head 102 is performed by effect of the positivelocking by a symmetrical tooth or pawl 106 that cooperates with a doublesawtooth toothing 107A, 107B realized on both the larger sides of thetail 103. As it is usual, the tail end 104 of the strap 101 is withouttoothing and tapered to facilitate its insertion into the head 102 ofthe strap 101 in the initial steps of the locking operations of a bundleof cables or conductors.

In a preferred embodiment, the connection part 108, 109 is radiused witha radius R for a better distribution of the bending stresses at themoment of locking of the strap on a bundle of cables and for preventingits breakage near the head owing to large stresses that may occur, asmentioned above, at the moment of fastening, or during the useful lifeof the strap in the operative conditions.

With reference to FIGS. 9 and 10 there will be shown with more detailsthe strap according to the invention. Reference numbers equal to thoseof FIGS. 7 and 8 show corresponding parts.

The symmetrical head 102 comprises a channel 10 with symmetrical entryopenings 105, for the passage of the tail 103. At the interior of thechannel 110 there is provided a ridge for the positioning of thetoothing 107A, 107B of the tongue 103, and a tab or movable retainingtooth or pawl 106 on a virtual hinge comprising a root 111 radiused tothe body of the head 102, a thinned part 112 with two shoulders 113 and114, and a locking tooth proper 115. In addition there is provided apositioning tooth T located substantially opposite to the locking tooth115.

During the locking operation, the whole of the retaining tooth 106 mayrotate either in a clockwise or counterclockwise direction with respectto the rest position shown in FIG. 9 according to the direction ofintroduction of the tongue 103 within the cavity provided in the head102.

The parts 116, 117 of connection of the head 102 with the tail 103 areradiused for decreasing the stresses as described above.

In FIG. 10 there is shown the structure of FIG. 9 in one of the twopossible locking conditions. For simplicity of disclosure, there isshown only one locking condition; the other locking condition ismirror-like symmetrical, owing to the symmetry of the locking structureaccording to the invention, i.e., it is a simple mirror image that willnot be disclosed in detail.

In this FIG. 10, the cable tie strap is shown in a locking condition inwhich the retaining tooth 106 is shown in the direction of theintroduction of the tail 103 in direction shown by the arrow F3. Anintroduction of the tail 103, with the symmetrical toothing 107A, 107Bcauses the retaining of the retaining tooth 106 that prevents theextraction of the tail 103.

The radiused parts 116, 117 on centers C1, C2 allow, as stated above,the structure to be rendered more rugged, and also allow a better matingwith the cables of the bundle, one of which is shown in 20. The assemblysituation is shown in FIG. 5 and a further explanation is deemedunnecessary.

In FIGS. 12A to 12D there is shown a second embodiment of the presentinvention, relating to the head 102. Since the modification shown inFIGS. 12A-12D relates only to the locking tooth or pawl 106, there willbe disclosed in detail only the structure of the latter, leaving out theremainder of the head 102, which is identical to what has been disclosedhereinbefore.

For a better understanding of the modifications according to FIGS.12A-12D, it is advisable to mention a problem that appears with theconventional cable tie straps and also in those described above.

When the cable tie strap has been locked, the strength necessary for thelocking is concentrated, in practice, in the virtual hinge part 106(FIG. 9). This part 106 cannot be too strong, otherwise the introductionand locking operation for the strap would be difficult. At the same timeit cannot be too yielding, otherwise the quantity of material that hasstrength in the fastening step would be insufficient. The structure anddimensioning of part 106 constitutes therefore a critical element in thedesign and production of this kind of cable tie straps.

The structure shown in FIGS. 12A-12D enables this problem to beovercome.

As it is shown in these figures, the locking tooth 106′ comprises a rootpart 120 connected with an elastic hinge 121 to a locking body propershaped as a symmetrical polygonal star. This locking body comprisesshaping 122, 122′; 123, 123′; 124, 124′. As it is shown in FIG. 12B,during the insertion operation of the tongue within the head 102, thebody 106′ rotates to the left allowing the passage of the tongue 103 andof the tooth 107A. In this connection, owing to the flexibility of theelastic or virtual hinge 121, the shapings 123′, 124′ will be carriedoutside the outline of the tooth 107A, allowing the introduction of thetongue 103 in the direction shown by the arrow F4.

In the condition of simple engagement, the tail 106 will have two teethl07A′, 107A″, in engagement with the shapings 124′ and 123′ (see FIGS.12A and 12C). In this way the positioning is much more stable withrespect to the conventional construction.

In condition of finished fastening and/or particular stresses when thecable tie strap is in the operational condition, stressed by the forceindicated by the arrow F5, the locking tooth 106′ will be in engagementwith the shapings 124′, 123′ with the tooth 107A′, 107A″, but owing tothe yielding of the elastic hinge 121 the shaping 122 will rest againstthe left part of the root 120. In this way the strength to the tear ofthe tail 106′ will be assured not by the hinge 121 as in theconventional construction, but by the interlocking of the shapings 124,123′, to teeth 107A′, 107A″, shaping 122 and root 120. Consequently thestrength to the tear will be guaranteed by the strength of the tongue106 and not by the hinge 121 with an increase of reliability of thebinding extremely higher than that of the conventional cable tie straps.

It will be clear that the construction and the operational principle ofthe construction according to FIGS. 12A-12D may also be applied toasymmetrical cable tie straps of the conventional kind.

With reference to FIGS. 13, 14 and 14A a further embodiment of theself-locking tie strap according to the present invention will now bedisclosed.

The head 200 of this tie strap is somewhat similar to the one disclosedwith reference to FIGS. 6A and 6D. The head 200 comprises a head part201 coupled with bars 202, 203 to a connection body 204 that supports atongue or pawl 205 carried by a hinge stem HS. The tongue or pawl 205 isprovided with pairs of symmetrical teeth 206, 207 and 206A, 207A,arranged to mate with a toothing 208, 208A, provided on the tail part209 of the tie strap. The structure id designed so that the tongue orpawl 205 in the locked condition engages a pair of the teeth of thetoothing 208, 208A depending on the direction of insertion of the tail209 within the head 200. The general operation of the structure shouldbe clear from the foregoing description and will not be repeated here.

With reference to FIG. 14A now the specific operation of the tie strapshown in FIGS. 13 and 14 will be disclosed.

In FIG. 14A the same references quoted in FIGS. 13 and 14 will indicatethe same parts.

The tail part 209 inserted into the head 200 along the direction shownby the arrow F14 will bring the teeth 208 along the cavity defined inthe head 200. The series of teeth 208A will engage the teeth 206, 207 ofthe tongue or pawl 205, if the tail part 209 is inserted along thedirection of the arrow F14 (shown pointing to the left in FIG. 14A). Theconverse will occur with teeth 208 and the teeth 206A, 207A if the tailis inserted in a direction opposite to that of the arrow F14, i.e. fromthe left in FIG. 14A.

When a pull force schematically represented by the arrow P is exerted onthe tail 209 caused by the binding force on a bundle of cables aspreviously disclosed, the hinge stem HS will undergo an elasticdeformation so that two teeth of the series 208A will engage both theteeth 208 and 207 provided on the pawl 205. At the same time owing tothe elastic yield of the hinge stem HS, a part 205A will rest againstthe body of the head of the strap shown in 200A. In this way the forceexerted by the pull force P will be distributed on three points(208A-206; 208A-207; 205A-200A), thus relieving any stress on the hingestem HS that substantially in such condition performs the sole operationof keeping the parts 200, 208A, 205 in the correct position for anadvantageous distribution of the forces in play.

In this way the hinge stem HS may be manufactured so that it is moreelastically pliable. This fact proves advantageous when these tie strapsare utilized with automatic insertion tools.

With reference now to FIGS. 15 and 16, a further embodiment of theself-locking tie strap according to the present invention will bedisclosed.

The head 300 of this tie strap is also similar to the one disclosed withreference to FIGS. 6A to 6D. The head comprises a head part 301 coupledwith bars 302, 303 to a connection body 304 that supports a tooth orpawl 305 carried by a hinge stem 306. The tooth or pawl 305 is providedwith pairs of symmetrical teeth 306, 307 and 306A, 307A, arranged tomate with a toothing 308, 308A provided on the tail part 309 of the tiestrap. The structure is designed so that the tooth or pawl 305 in thelocked condition engages a pair of the teeth of the toothing 308, 308Adepending on the direction of insertion of the tail 309 withing the head300.

In this embodiment the hinge stem 306 is made relatively thin in orderto reduce the insertion force for the tail 309 within the head 300. Thestresses due to the binding action are counteracted by ridges 310, 311and 310A, 311A that rest one against the other relieving from excessivestresses the hinge stem 306.

With reference now to FIGS. 17 and 18, a further embodiment of theself-locking tie strap according to the present invention will bedisclosed, and that has a head with a doubly symmetrical structure.

The head 400 comprises a head part 401 coupled with bars 402, 403 to aconnection body 404. Both the head part 401 and the connection body 404each support a tongue or pawl 405, 405A, respectively, carried by hingestems 406, 406A. The teeth provided on the pawls 405, 405A are arrangedto engage in the locked condition with a tooth on each side of thetoothings 408, 408A provided on the tail part 409 regardless of thedirection of insertion of the tail 409 within the head 400.

In this way there is a symmetry of operation insofar as the insertion ofthe tail into the head is concerned and also a symmetrical distributionof the stresses due to the binding action when the tie strap is in theoperative condition. The same considerations above discussed withreference to FIG. 14A will be valid for this embodiment and a furtherdiscussion is considered not necessary.

Now, with reference to FIGS. 19 and 20 a modified tail part convenientfor use in the above tie straps will be disclosed.

As it is well known to a person skilled in the art, when tie straps ofthe type in question are used, often the operator encircles a bundle ofcables or wires with a tie strap in a slack condition and subsequentlyperforms the tightening of the tie straps in the desired position alongthe bundle.

With the irreversible, lock tie straps known in the art, an extra tiestrap too many, even if placed in a slack condition, cannot be removedif considered unnecessary, owing to the irreversible mechanism due tothe cooperation between locking pawl and toothing on the tail. Anunnecessary tie strap can only be removed by cutting it and throwing itaway as scrap with a loss of money.

The tail for tie straps shown in FIGS. 19 and 20 allows a preliminaryreleasable (non-irreversible) placement of the tie straps when these arenot completely tightened in order to remove any unnecessary tie strappermitting that the same be reused for another strapping of cables ofwires.

The tail part shown in FIGS. 19 and 20, shown generally in 500,comprises a first part 501 adjacent to the head of the tie strap (notshown) and a second part 502 adjacent to the very end 503 of the tail.

The first part 501 is provided on both sides with toothings 504, 504Athat engage irreversibly with the pawl or pawls provided in the head ofthe tie strap, and with a number of gently sloped teeth 505, 505A on thepart 052. The slope at the left in FIG. 20 is such that an irreversiblelocking does not occur and the partially inserted or slack part of thetail may be removed, if necessary, from the head of the tie strap.

Further, the very end 503 of the tail 500 is provided with a taper 506to facilitate the insertion of the end 503 of the tail 500 into the gapon the head of the tie strap, gradually overcoming the elasticity of therelatively stiff pawl or pawls.

Various other modifications to the foregoing disclosed embodiments willnow be evident to those skilled in the art. Thus, the particularlydescribed preferred embodiments are intended to be illustrative and notlimited thereto. The true scope of the invention is set forth in thefollowing claims.

What is claimed is:
 1. A cable tie comprising: an elongate generallyplanar strap body having a tail at one end and a head at the other end,said strap having strap teeth on opposed planar body surfaces; anelongate strap passageway in said head having a pair of opposed openingsat each end for insertion of said tail into said passageway from eitherdirection; a deflectable locking element supported by said head andextending into said passageway, said locking element being engageablewith said strap teeth of an associated one of said opposed surfaces uponinsertion of said strap into said passageway in either said direction soas to place said locking element and said strap teeth of said associatedsurface in direct non-releasable locking engagement.
 2. A cable tie ofclaim 1 wherein said locking element includes a deflectable hinge memberand a locking member integrally formed with said deflectable hinge forengagement with said strap.
 3. A cable tie of claim 2 wherein saidlocking member is symmetrically formed having oppositely directedlocking teeth.
 4. A cable tie of claim 3 wherein said symmetricallyformed locking member includes at least two teeth on opposed surfacesthereof, said teeth of one surface for engagement with two teeth of oneof said opposed surfaces of said strap upon insertion of said strap intosaid passageway.
 5. A cable tie of claim 4 wherein said locking teeth ofsaid other surface being engageable with said head for reducing hingestress.